Association of symptomatic· human infection with toxoplasma gondii with imbalance of monocytes alldantigen-specific T cell subsets

Abstract

During. recent symptomatic toxoplasmosis, alterations in quantity and function of mononuclear cellsin peripheral blood were observed. Flow cytofluorometric analysis and differential leukocyte counts revealed increasedabsolute numbers of T8 + cells, Leu 7 + (natural killer/killer) cells, and monocytes. T4+ cells and HLA-DR+ cells were not significantly changed. T4/T8 cell ratios were reversed in symptomatic toxoplasmosis (0.7 ± 0.3) and normal in chronic infection (1.7 ± 0.5). Toxoplasma antigen induced higher numbers of T8 + and TQl + cells in four T cell lines from two individuals with symptomatic infection than in five T cell lines from three individuals with asymptomatic infection. Eight cloned T cell lines produced γ interferon in an antigen-specific fashion and in higher amounts when they originated from an asymptomatic subject than from a symptomatic subject. These results indicate that marked alterations in properties of immunoregulatory cells are characteristic of recent symptomatic toxoplasmosis. The transient immune dysfunction may be a major part of the observed disease and/or a feature of successful parasitism. © 1986 Oxford University Press.